Conventionally, there is known a brake control device for a railway vehicle, comprising as a brake system for service operation; a pressure control section which outputs a brake command signal (electric signal), a solenoid valve which outputs a brake command pressure (air pressure) according to the brake command signal, and a relay valve which, using the brake command pressure output by the solenoid valve as a control pressure, applies amplification accordingly and outputs the resulting air pressure to a brake cylinder. As a brake system for emergency operation, the brake control device comprises a variable load valve which detects pressure variation in proportion to the total weight of the vehicle including movable load such as passengers and cargo, and provides this detected output to the relay valve.
Typically, because the space for mounting the brake control device on the vehicle is small, there is a problem in how to reduce the size of the device while still maintaining its performance. Schemes are offered such as respectively fixing a relay valve, a double check valve, and a variable load valve on a pipe seat, and accommodating these inside of a housing (casing or the like), or building the variable load valve into the relay valve. Moreover, these are stacked so as to be in blocks, with the above respective constituent elements related as much as possible (refer for example to Japanese Patent No. 4310149 and Japanese Patent No. 4485347).
However, the respective blocks are fixed independently (in block units) with sequential bolts and the like. Therefore, there is the problem in that the assembly operation is complicated, furthermore, removal of the bolts is cumbersome.
In particular regarding the variable load valve, so as to output an appropriate pressure with respect to the pressure (movable load) input from an air spring that detects the movable load of passengers, cargo and the like, it is necessary carry out correction (maintenance) of the output value with respect to the input value, periodically or as required.
However, in the brake control device described above, when correcting the variable load valve, it is not possible to access the variable load valve unless all or a part of the components that are arranged around the variable load valve are removed, making the calibration operation complicated.
Therefore it is an object of the present invention is to provide a brake control device in which maintenance can be performed by independently removing the variable load valve without disassembling the components of the main unit.